The main long-term objectives of this research project encompass the biochemical and physiological parameters of several complex macromolecular cell surface components, viz. the poly-gamma-D-glutamyl capsule of Bacillus licheniformis; the sialic acid containing polymers of Escherichia coli and the penicillin binding components in methicillin resistant, Staphylococcus aureus. During the past two years, the main emphasis of this work has been concerned with the chemistry and biosynthesis of the poly-gamma-D-glutamyl capsule of B. licheniformis and to a lesser extent with the biochemical basis of methicillin resistance in S. aureus. On the basis of the work already accomplished, the future objectives are a logical continuation. These objectives include: 1) elucidation of the precise molecular events associated with the mechanism of activation, racemization and polymerization of the unique poly-gamma-D-glutamyl capsular polymers. This will involve a detailed analysis of the mechanism involved in the dissociation and reassembly of the particulate cell envelope fraction; the determination of the direction of polymer synthesis, and the possible involvement of "acceptor" molecules to which the initial glutamyl residues are attached and on which subsequent polymerization occurs; 2) the possible involvement of the capsule in bacteriophage infection; 3) the purification and characterization of the extracellular poly-gamma-D- glutamyl depolymerase; and 4) characterization of the properties of the cell envelope associated penicillin binding components in methicillin resistant strains of S. aureus. Studies will be initiated to determine the location within the cell envelope and the possible involvement of polyisoprenol derivatives as intermediates in the biosynthesis of the sialic acid containing polymers in E. coli. These studies will be directed ultimately towards elucidating the relationship of these components to other cell surface macromolecules (e.g. lipopolysaccharides) and to relate their presence to the structure and function of the cell envelope in pathogenicity.